Experimental model of hyperargininemia Ⅱ. Identification of guanidinosuccinic acid in urine of the arginine loaded rabbit and a possible pathway of its formation

Authentic guanidinosuccinic acid was converted into dimethylpyrimidyl derivative by reaction with acetylacetone, the carboxyl group was esterified by butylalcohol, and this derivative was analysed by the GC/MS technique. Then guanidinosuccinic acid was identified in urine of arginine loaded rabbit by means of selected ion recording. On the other hand, aspartic acid and isomolar of arginine was loaded simultaneously to rabbit, and a higher level of guanidinosuccinic acid was detected in the urine of 2 or 3 days and one week after. This fact suggest that guanidinosuccinic acid could be produced by transamidination of aspartic acid, receiving amidine group of arginine.